Underwater pipeline-riser clamps for use on oil and gas pipelines

ABSTRACT

THE INVENTION CONSISTS OF DOUBLE CLAMP ASSEMBLIES WHICH HAVE SEGMENTS PIVOTED RELATIVE TO EACH OTHER FOR ATTACHING GAS AND OIL VERTICAL PIPELINES TO PLATFORMS LOCATED OFFSHORE. THE CLAMPS ALLOW SWIVELLING ADJUSTMENT OF A PIPE RELATIVE TO THE LEG MEMBER OF A PLATFORM TO WHICH IT IS TO BE AT-   TACHED. THE CLAMPS MAY INCLUDE SCREW-ADJUSTED LINK MEANS FOR REGULATING THE RELATIVE ORIENTATION OF THE CLAMPING SEGMENTS.

H. J SAVOIE, JR UNDERWATER PlPEhlNE-RLSER CLAMPS FOR USE ON OIL AND GASPIPELINES 4 Sheets-Sheet l lN\-ENTOR. H/L BERT J 634M075, :1?

A T TOR NE Y5.

ay 23, 1972 H. J. SAVOIE, JR

UNDERWATER PIPELINE-RISER CLAMPS FOR US ON OIL AND GAS PIPELINES 4Sheets-Sheet 2 Filed Aug. 28, 1970 INVENTOR. HMEEFT SAVO/E 6/8,

May 3, 1972 H. J. SAVOIE. JR 3,664,621

UNDERWATER PlPELulflE-RISER CLAMPS FOR USE ON OIL AND GAS PIPELINES 4Sheets-Sheet 3 Filed Aug. 28, 1970 MB w 6%, \1.

90 6 6 85 (92 6,4 INVENTOR.

///L BERT J (9/2 I/O/E, JR.

ATTORNEMS.

23, 7 H.,,J. SAVOIE, JR

UNDERWATER PI'FBLlNE-RISEK CLIAMPS FOR USE ON OIL AND GAS PIPELINE S 4Sheets-Sheet 4 Filed Aug. 28, 1970 ATTORNEYS.

INVENTOR.

nnnnnnnnnnnnnnni United States Patent 3 664 621 UNDERWATER PIPELINE-RISER CLAMPS FOR USE ON 011. AND GAS PIPELINES Hilbert J. Savoie, In,P,0. Box 98, Boutte, La. 70070 Filed Aug. 28, 1970, Ser. No. 67,864 Int.Cl. F161 3/10 US. Cl. 24874 R 7 Claims ABSTRACT OF THE DISCLOSURE Theinvention consists of double clamp assemblies which have segmentspivoted relative to each other for attaching gas and oil verticalpipelines to platforms located offshore. The clamps allow swivelingadjustment of a pipe relative to the leg member of a platform to whichit is to be attached. The clamps may include screw-adjusted link meansfor regulating the relative orientation of the clamping segments.

This invention relates to clamping devices, and more particularly toclamping devices for clamping pipes to adjacent supports.

A main object of the invention is to provide a novel and improvedclamping assembly especially adapted for clamping gas and oil verticalpipelines to platforms located offshore, the clamping devices beingrelatively simple in construction, being easy to install, and havingsegments which are adjustable relative to each other.

A further object of the invention is to provide an improved clampingassembly for attaching gas and oil vertical pipelines, and similarconduits, to adjacent supports, such as leg elements of platformslocated offshore, the clamps being relatively easy to manipulate so thatthey can be readily installed by divers, being durable in construction,and being inexpensive to fabricate.

A still further object of the invention is to provide an improved clampassembly especially suitable for attaching gas and oil verticalpipelines to platforms located offshore, the clamp assemblies involvingrelatively few parts, having a high degree of adjustability so that theyallow pipes to be secured to their associated supports even when thepipes are skewed relative to the supports, the clamp assemblies beingrelatively compact in size, being relatively light in weight, and havingmeans for easily and efiiciently adjusting the relative orientations oftheir various segments.

Further objects and advantages of the invention will be apparent fromthe following description and claims, and from the accompanyingdrawings, wherein:

FIG. 1 is a top plan view of an improved multiplesegment type clampingassembly constructed in accordance with the present invention.

FIG. 2 is a vertical cross-sectional view taken substantially on theline 2--2 of FIG. 1.

FIG. 3 is a perspective view of one of the sinuouslycurved body elementsof the clamping assembly of FIGS. 1 and 2.

FIG. 4 is a fragmentary top-plan view of one end portion of a modifiedform of clamping assembly according to the present invention.

FIG. 5 is a vertical cross-sectional view taken substantially on theline 5-5 of FIG. 4.

FIG. 6 is a top-plan view of another modification of a multiple-clampassembly according to the present invention.

FIG. 7 is a vertical cross-sectional view taken substantially on theline 77 of FIG. 6.

FIG. 8 is a top-plan view of still another modified form of amultiple-clamp assembly according to the present invention.

'ice.

FIG. 9 is a vertical cross-sectional view taken substantially on theline 9-9 of FIG. 8.

FIG. 10 is a top-plan view of still another form of multi-clamp assemblyaccording to the present invention which is provided with swivel meansallowing the assembly to be utilized to secure a vertical riser to abrace member running at any angle.

FIG. 11 is a top-plan view of another form of multipleclamp assemblyaccording to the present invention, said form being somewhat similar tothat shown in FIG. 10, but without the swiveling feature.

FIG. 12 is a top-plan view of still another form of multiple-clampassembly, according to the present invention, employing screw-adjustmentmeans for regulating the spacing between the clamp assembly sections.

FIG. 13 is a front elevational view of the clamp assembly of FIG. 12.

FIG. 14 is a top-plan view of still another form of multiple-clampassembly according to the present invention, employing screw-adjustmentmeans for regulating the spacing between the clamping segments of theassembly.

FIG. 15 is a top plan view of still another form of multiple-clampassembly according to the present invention, wherein the clampingsegments are angularly adjustable relative to each other.

FIG. 16 is a vertical cross-sectional view taken substantially on line1616 of FIG. 15.

FIG. 17 is a vertical cross-sectional view taken substantially on line1717 of FIG. 16.

FIG. 18 is an enlarged vertical cross-sectional detail view takensubstantially on line 1818 of FIG. 16.

A prime purpose of the present invention is to provide clamps intendedto be utilized under water to attach gas and oil vertical pipelines(also called risers) to platforms located offshore.

Oil and gas platforms located offshore are usually connected togetherwith pipelines of varying sizes. These pipelines are usually laid underthe surface of the water below the mud line. When the pipelines arebrought from the mud line to the top of the platforms it is necessary toattach them to the platforms with some form of bracing or clamps. Thepipeline sections from the mud line to the top of the platform arecalled risers. These risers are usually attached to the platforms byusing clamping devices .which attach to the risers and usually to themain leg members of the platform.

In some instances, a riser when of a small enough size, can be attachedto a horizontal bracing member of the platform by a clamping device.

Risers in modern use vary in size from a diameter of several inches to adiameter of two or three feet. It is especially difiicult to attach thelarger risers to the platforms because of the necessity for installationunder water by divers. Furthermore, it is virtually impossible tocompute, prior to installation, the exact distance that the verticalriser will be from the main leg of the platform to which it is to beattached. I

In the oil and gas industry, clamps in current use are relatively bulkyand are difiicult to install. Also, the clamps currently in use must befabricated to exact specifications for successful attachment of thevertical risers to the main leg members of the platforms. Theserequirements create further difliculties in the installation of therisers, as will be presently described.

Further evidence for the need for improved clamp assemblies are thefollowing:

(1) Most of the clamps are installed under water, and therefore it isnecessary to utilize marine divers; the cost of marine divers is greatand the cost increases proporv tionately with the depth of the water inwhich the clamp is to be installed. Additionally, large amounts ofexpensive equipment are necessary to assist the diver in installation ofthe clamps.

(2) The time involved from the start to the finish in installing avertical pipeline or riser adjacent to an existing platform is criticalin that the most significant items of expense are the salaries andrental fees paid to divers and owners of marine equipment, such asderrick barges, tugboats, crew boats, supply barges, and engineering andfabricating equipment, and the cost for the administration of theinstallation of the abovementioned apparatus.

It is therefore apparent that improved clamps which will save time ininstallation will also save the petroleum companies and installationcontractors concerned, considerable amounts of money.

The diver installing the clamps connecting the vertical risers to theadjacent platform usually works alone. The clamps in current use are ofconsiderable size, sometimes weighing hundreds of pounds. The size ofthe clamp to be utilized is usually determined by the size of thevertical riser and the size of the main leg member of the platform towhich the riser is to be attached. Main leg members of platforms usuallyrange in diameter from 36 inches to 60 inches. As previously mentioned,the vertical pipelines or risers may range in size from a few inches toas large as two to three feet in diameter, and in some instances theyexceed three feet in diameter.

The clamps utilized to attach the vertical riser to the platform mainleg member are placed at intervals starting at the bottom near the mudline, and are placed as required along the vertical pipeline or risersso that the riser is firmly attached to the main leg member of theplatform. The depth of the water surrounding the oil or gas platform andthe size of the vertical riser will usually determine the size andnumber of clamps to be installed. The time involved in installing theclamps will vary, depending upon the depth of the water to be worked inand the size of the clamps to be utilized.

The clamps forming the present invention will allow a diver to installall of the necessary clamps on a riser in one dive in water as deep as200 feet. The various forms of the clamps of the present invention willnow be described in detail, with reference to the accompanying drawings.

Referring now to FIGS. 1, 2 and 3, 20 generally designates a typicalriser clamp assembly according to the present invention. The assembly 20comprises two parts each having a generally S-shaped configuration whichare pivotally connected together in interleaved relationship at theircenter portions to define pairs of opposing generally semi-circularjaws. Thus, the first generally S- shaped member comprises a pair ofsinuonsly curved flat bar elements 21, 21, each having the shape shownin FIG. 3, which are rigidly secured together in parallel spacedrelationship, as by means of a spacer block 22 rigidly connected betweentheir respective semi-circular jaw portions 24, 24. The cooperatinggenerally S-shaped member comprises sinuonsly curved similar flat barelements 25, 25 having the respective generally semi-circular jawportions 28, 28' which respectively oppose semicircular jaw portions 24,24', as shown in FIG. 1. Generally semi-circular jaw elements 28 arerigidly connected together by blocks 22' similar to those employed forthe jaw elements 24. The pairs of members 21, 21 and 25, 25 areinterleaved and are pivotally connected at their center portions by apivot bolt 26, as shown in FIG. 2, and suitable spacer washers 27, 27surround the bolt 26 and are located between the crossing portions ofthe sinuous members as illustrated in FIG. 2. The bolt 26 is providedwith a fastening nut 29 having a handle loop 30.

Each flat sinuonsly curved member is provided at its end with anoutwardly extending notched lug 3'1. Hinged at 32 to the pairs ofsemi-circular jaw elements 28, 28 is a bracket 33 to which is secured abolt 34 engageable between the lugs 31, 31 of the jaws 24, 24 and beingprovided with a nut 35. The bolt 34 is provided with a rectangularbridging washer 36 which is receivable in the notches of the lugs 31carried by the jaws 28, and a similar bridging washer '37 is providedbeneath the nut 35 and is receivable in the notches of the lugs 31 ofjaws 24. Thus, the jaws 28 and 24 may be clamped around a leg memberassociated with an offshore platform, as above described, with theopposite pairs of opposing jaws 24' and 28' engaged around a verticalriser. Said members 28' and 24 are provided with similar lockingstructure consisting of notched lugs 31 and a hinged bracket 36'carrying a clamping bolt 34- provided with a securing nut 35' and havingthe bridging washers 36' and 37' engageable in the notches of the lugs31 in the manner illustrated in FIG. 1.

Thus, the assembly 20 may be used by first swinging the opposinggenerally S-shaped members thereof to open positions, such as shown indotted view in FIG. 1, and then engaging the sets of opposing jawsrespectively around the vertical platform leg member and the verticalriser to be clamped thereto, after which the generally S-shaped membersare swung together in scissor fashion and are fastened by their clampingbolts. The bolts 34, 34' may be swung into clamping positions betweenthe sets of notched lugs 3-1 after the jaws have been swung inwardly toembrace the platform leg member and vertical riser, respectively. Due tothe two-piece construction of this assembly, which enables the parts tobe pivoted in scissor fashion, this design allows the use ofhorizontally acting power means to close the clamp segments, forexample, allows the use of a hydraulic cylinder suitably engaged withthe sets of notched lugs of one set of opposing jaws to close the jawswhile the diver secures the bolts on the ends of the opposite jaws. Theuse of hydraulic power allows the clamp to be closed in the event thereis a slight variation in distance between the leg member and the riseras compared with the nominal distance between sets of the opposing pairsof jaws. After the jaws at one have been bolted, the hydraulic cylinderdevice may be removed and the adjacent hinged bolt may be employed toclamp the jaws previously engaged by the hydraulic cylinder device.

FIGS. 4 and 5 illustrate a variation in structure as compared with FIGS.1, 2 and 3, wherein the interleaved ends of one set of jaws may beapertured to receive a wedge 38, instead of employing the notched lugs31 and the hinged bolts. Thus, this enables the diver to secure theclamping assembly closed after it has been closed by the hydrauliccylinder, whereupon he can remove the hydraulic cylinder and completethe securement at that end with the hinged bolt and nut arrangementdescribed in connection with FIGS. 1, 2 and 3. For example, the jaws 24,24 and 28, 28 may be provided at their ends with registrable apertures39 adapted to receive the wedge 38, whereas the jaw elements 28' and 24may be provided with the structure shown in FIG. 1, including thenotched lugs 31 and the hinged bracket 33' carrying the bolt 34'. Withsuch an arrangement, the hydraulic cylinder device is employed to closethe jaws at the ends of the elements 28' and 24', after which the wedge38 is inserted through the apertures 39 to hold the clamping deviceclosed. The hydraulic cylinder device may then be removed and thesecurement of the clamp may be then completed by using the hinged bolt34 and the parts associated therewith to lock the jaw elements 28' and24' together in the manner previously described.

FIGS. 6 and 7 illustrate another form of the invention designatedgenerally as 40. The clamping assembly 40 comprises a first pair ofgenerally C-shaped jaws 41 and 42 and a pair of additional generallyC-shaped jaws 43 and 44, the jaws being pivoted together by a commonpivot bolt 45 defining a pivotal junction of the jaws. Thus, thegenerally C-shaped jaw assembly 41 comprises a pair of generallysemi-circular flat bar elements 46 and 47, rigidly secured in spacedparallel relationship by being connected to a spacer block 48 securedbetween their intermediate portions. The opposing generally C-shaped jawassembly 42 is similarly formed, but is provided with an upstandingbracket plate 49 to which is journaled a peripherally grooved pulley 50adapted to be employed with a suspension cable, not shown, to facilitatehandling the assembly. The upper generally semi-circular bar member 46of the opposing jaw assembly 41 is provided with an upstanding loop 51adapted to be similarly employed with a cable, or the like, for handlingthe assembly.

The generally C-shaped jaw assemblies are provided at their free endswith notched lugs, shown at 52, similar to those provided in thepreviously described forms of the invention, to be employed with pivotedsecuring bolts 34 and 34 carried by hinged bracket members 33 and 33',utilized in the same manner as in the embodiment of FIGS. 1, 2 and 3.

As shown in FIG. 7, the flat generally semi-circular bar elements of thejaws have interleaved end lugs 54 which are apertured to receive thepivot bolt 45, being thus pivotally connected together by said pivotbolt. The apertured pivot lugs 54 at the ends of the bars thus cooperatewith each other to maintain the fiat bars in parallel planes. As in thepreviously described form of the invention, the pivot bolt 45 isprovided with a nut 29 having a handle loop 30.

The assembly 40 is designed for the purpose of connecting the verticalmain leg member of a platform to a vertical riser. Thus, the jaws 42 and41 are engageable with the platform vertical leg member and the jaws 43and 44 are similarly engageable with a vertical riser to be clampedadjacent to the platform. vertical leg member. The sets of jaws 41 and42 can be manipulated independently of the jaws 43 and 44, so that thetwo sections of the clamp can be securely attached either to the riseror the main leg of the platform independently of each other.

It will thus be seen that the jaws 41 and 42 may be connected to thevertical leg of a platform, shown at 57 in FIG, 7, and the jaws 43 and44 may be attached to a vertical riser, shown at 58 in FIG. 7, in anydesired sequence of operations, because the respective pairs of jaws canbe independently manipulated.

FIGS. 8 and 9 illustrate a modified form of the clamp assembly shown inFIGS. 6 and 7 wherein the respective pairs of jaws 41, 42 and 43, 44 areconnected together by link bars to define a variable distance stand-01farrangement to allowthe assembly to be used to connect a riser to avertical platform leg member when the exact distance between the riserand the leg member cannot be accurately determined prior to theinstallation of the clamp assembly. Thus, a plurality of identical fiatlink bars 59 are interleaved with the apertured end lugs 54 of the clampbars, respective pivot bolts 60, 60 being employed to connect respectivesets of opposing jaws to the ends of the link bars. The uppermost linkbar 59 may be provided with an upstanding handle loop 61, as shown inFIGS. 8 and 9.

The clamp assembly of FIGS. 8 and 9 is especially designed for use as afirst clamp assembly at the mud line. As previously discussed, whenpipelines are installed under the mud line, that portion of the pipelinefrom the mud line to the top of the platform is called the verticalriser. When installing the pipelines of vertical risers, it isimpossible to compute the exact distance the vertical riser will be fromthe main leg of the platform to which the riser is to be attached. Thedistance between the vertical riser and the main leg of the platform atthe mud line may vary from one to three feet, and in some instancesbeyond three feet, along the length of the riser. Because of theabove-mentioned variations, and because of the size of the risers, someof which have a diameter from two to three feet, and furthermore,because of the great depths at which the vertical riser is installed insome instances, it is nearly impossible to predetermine and prefabricatethe size of the clamp necessary to connect the riser to the main leg atthe mud line. According to the practice heretofore employed, numerousdives are necessary in order to connect the vertical risers to the mainleg of the platform, using the clamps of the prior art. Thus, when usingsuch prior art clamps, the dllVBl must measure the distance between theriser and the main leg at the point of installation and send thisinformation to the clamp fabricator. After the fabrication of the clampthe diver must then proceed to install the clamp on the riser and themain platform leg. If the clamp is not properly fitted and has no meansfor adjustment, a new measurement must be made and the clamp must bereturned to the manufacturer for refabrication. The above process mustbe continued until the clamps are properly fitted.

The above-mentioned problems are corrected by employing a double pivotclamp assembly of FIGS. 8 and 9. The double pivot assembly allows theclamp to be maneuvered so that it may be fitted to the riser and mainleg of the adjacent platform with ample allowance'for variation indistance between the riser and the main leg. Thus, the respective setsof jaws 41, 42 and 43, 44 may be maneuvered as required and then belocked in place by their fastening bolts 34, 34'.

The embodiment illustrated in FIG. 10 is generally similar to that ofFIGS. 8 and 9 except that the link bars 59 are replaced by a swivelassembly to permit the cooperating jaw assembly 41, 42 to be swiveledwith respect to the other cooperating jaw assembly 43', 44'. Thecooperating jaw assembly 41, 42 may be similar to that shown in FIGS. 8and 9 and is pivotally connected by the pivot bolt 60 to a bracket 62which may be of general U-shape having a transverse bight portion 63which is pivotally connected by a swivel bolt 64 to an end wall 65 of abox-like member 66. The member 66 is received between the generallysemi-circular top arm 67 and the generally semi-circular bottom arm 68of the jaw assembly 44. As shown in FIG. 10, the generally semi-circulartop arm 69 and the generally semi-circular bottom arm 70 of the jawassembly 43 are respectively located above and below the arms 67 and 68,with the inner end portions of the upper arms 67 and 69 superimposed onthe top wall of the box-like member 66 and the inner portions of thelower arms 68 and 70 superimposed subjacent the bottom wall of boxmember 66. The connecting pin element 60' extends through saidsuperimposed inner end portions of the arm, as well as the top andbottom Walls of the boxlike member 66 to define a pivotal connection forthe jaw assembly 43', 44. As is clearly shown in FIG. 10, the pivotalaxis of the swivel bolt 64 extends perpendicular to both the left pivotpin element 60 and the right pivot pin element 60'. Thus, the jawassembly 43, 44' may rotate relative to the jaw assembly 41, 42, whichtherefore allows the clamp assembly to be utilized to secure a verticalriser to a brace member running at any angle.

The modification illustrated in FIG. 11 is also generally similar tothat shown in FIGS. 8 and 9 except that the cooperating pairs ofopposing jaw portions are arranged with their jaw axes perpendicular toeach other so as to secure a vertical riser to a horizontal bracemember. Thus, in FIG. 11, the cooperating generally semi-circular jaws41, 42, similar to those of FIGS. 8, 9 and 10, are pivotally connectedby the pivot bolt 60 to a rigid box-like member 66, the box-like member66 being received between the inner end portions of the innermostsemi-circular fiat bar elements of the jaws 41, 42, with the pivot bolt60 extending through the superimposed inner end portions of said flatbar elements as well as the intervening parallel walls of the box-likemember 66. The opposite end portion of the box-like member 66' isreceived between the members 67 and '68 of jaw portion 44, as in FIG.10, and the inner end portions of the jaw members 43, 44' are pivotallyconnected to the box-like member 66' by a pivot bolt 60' extendingperpendicular to the pivot bolt 60. The boxlike member 66' may beprovided with an outwardly projecting handle loop 72.

In the embodiments of FIGS. and 11, the outer end portions of the jawmembers may be provided with angle bracket 73 rigidly connected betweenthe outer ends of the flat generally semi-circular bar members thereofto receive the clamping bolts 74.

Although not shown in FIGS. 10 and 11, the clamping bolts 74 may bemounted on swinging arms hinged to the jaws in the same manner asdisclosed, for example, in FIGS. 8 and 9.

FIGS. 1'2 and 13 illustrate an embodiment of the invention adapted to beused to connect a vertical riser to a vertical platform leg withprovision for adjusting the distance between the clamping members inaccordance with the distance between the vertical riser and the platformleg to which it is to be clamped. Thus, the assembly, shown at 80 inFIGS. 12 and 13 is generally similar to that of FIGS. 6 and 7 in that itemploys a pair of cooperating jaw portions 41' and 42' generally similarto the jaw portions 41 and 42 in FIG. 6 and adapted to be clampinglysecured to a platform vertical leg.

The cooperating jaw assembly adapted to be clampingly secured to avertical riser comprises the opposed jaw portions 43' and 44 havingarcuately curved support arm portions whose inner ends are pivotallyconnected to the inner ends of the other pair of cooperating jawportions 41', 42' by the pivot bolt 45. As shown in FIG. 13, the arms 81and 82 of the jaw portion 43' receive therebetween the top and bottomarms 83 and 84 of the cooperating jaw portions 44. The arms 81 and 82have arcuately curved support portions 85 and 86 and the arms 83 and 84of the jaw 44' have arcuately curved support portions 87 and 88 receivedbetween the support portions 85 and 86, the inner ends of the supportportions being pivotally connected to the other cooperating jaws 41',42' by the pivot bolt 45. The assembly is provided with adjustable tiemeans connecting the arcuate support members 85, 86 to the jaw portion41' of the opposite cooperating pair of jaws. Thus, an arcuately curvedyoke member 89 has its arms pivotally connected at 90, 90 tointermediate portions of support elements 85, 86, and a threaded shaftelement 91 is rigidly secured to the bight portion of yoke member 89. Apivot lug member 92 is rigidly secured to and projects outwardly fromthe intermediate portion of the jaw 41' and a sleeve member 93 ispivotally connected thereto at 94. The shank element 91 extends throughthe sleeve member 93 and is provided with respective nuts 95 and 96located adjacent the opposite ends of the sleeve 93 for locking theshaft element 91 in an adjusted position with respect to sleeve 93. Thisallows the distance between the clamping axes of the cooperating jawelements 41, 42 and the jaw elements 43', 44 to be adjusted inaccordance with the distance between the riser pipe and the platform legelement to which it is to be clamped.

FIG. 14 illustrates a further embodiment similar to that of FIGS. 12 and13, wherein the lug member 92' rigidly secured to the jaw 41' projectsoutwardly in the same manner as in FIG. 12, but a similar lug structureis provided for the support arms of the jaw 43. Thus, the arcuatelycurved support arm portions of jaw 43' may be provided with outwardlyprojecting lugs 96 and a sleeve member 97 may be pivotally connectedbetween their top ends, as viewed in FIG. 4, by a transverse pivot pin98. One end of a threaded shaft member 91 is rigidly secured to asupport member 93' pivoted to the lug structure 92' by transverse pivotpin 94', the threaded shaft 91' extending through the sleeve member 97and being provided with the fastening nuts 95 and 96 similar to thoseemployed in the embodiment of FIGS. 12 and 13.

In the embodiment illustrated in FIGS. to 18, an arrangement is providedwherein a riser can be clamped to a leg or brace portion of a platformregardless of nonparallelism of the riser with respect to the element towhich it is to be clamped. Thus, the assembly designated generally at100 comprises a pair of generally V-shaped trunnion segments 101 and102, the segment 101 having the arcuately curved outwardly extendingopposite trunnion arms 103 and 104 and the trunnion segment 102 havingthe corresponding arcuately curved outwardly extending trunnion arms 105and 106. The arms 103 and 105 have aligned trunnion pins 108 and 109 attheir ends, projecting inwardly and having secured thereto the webs 110and 111 of respective generally semi-circular opposing clamping jaws 112and 113. Thus, as shown in FIG. 7, the clamping jaws are of generallyT-shaped cross-sectional shape and are secured to the trunnion pins attheir mid-portions. The arms 104 and 106 likewise support respectivegenerally semi-circular opposing clamping members 114 and 115 and aresimilar to the members 112 and 113. The respective clamping elements112, 113, 114 and 115 are thereby freely pivoted.

The generally V-shaped trunnion segments each comprises a pair ofparallel top and bottom plate members of identical shape rigidlyconnected by spacer blocks and located at the intermediate portions ofthe arcuate trunnion arms of the segments, as shown in FIG. 15. Top andbottom abutment plates 121, 122 are secured in the vertices of the armsof the trunnion segment 101, the top and bottom plates 121, 122 beingrigidly connected by an apertured vertical abutment plate 123. Anapertured abutment block 124 is provided in the vertex of the opposingtrunnion segmnt 102. A threaded clamping shaft 125 extends through theblock 124 and the plate 123. The shaft 125 is provided with an enlargedouter portion 126 defining an abutment shoulder 127 engaged against theblock 124, and a nut 128 is provided on the threaded shaft 125 outwardlyadjacent the plate 123, the nut nonrotatively fitting between the topand bottom plates 121 and 122, as shown in FIG. 18, whereby rotation ofthe shaft 125 in one direction causes clamping force to be exertedbetween the trunnion segments 101 and 102. The end of the enlarged shaftportion 126 may be provided with a hand wheel 129, and the hand wheelmay be provided with loops 130 at its periphery which may be employed inconjunction with a suitable cable connected to a power source forproviding external torque on the shaft 125 when required.

Thus, the respective pairs of jaw elements 112, 113 and 114, 115 may berespectively engaged around a fixed platform brace member and a riserpipe to be clamped thereto, after which the shaft 125 may be rotated bymeans of handwheel 129, and perhaps with the assistance of an externallypowered cable attached to loops 130, to tighten the assembly so as tocause the members 112, 113 and 114, 115 to tgihtly clamp a platformbrace member and a riser pipe, respectively. When the tighteningprocedure is completed, the diver removes the cable by detaching it fromthe loops 130.

For remote installation, the threaded shaft 125 may be operated byhydraulic, pneumatic or other mechanical means, and any suitable meansmay be employed for supervising the setting of the clamp assembly, forexample, by the use of underwater television for viewing the assembly asit is operated by such mechanical means.

It will be noted that because of the swivel cooperation between the jawelements 112, 113 and the arms 103, 105 and between the jaw elements114, 115 and the arms 104, 106, once the clamp has been installed, theriser may be raised or lowered without the necessity of loosening ortightening of the assembly or of making any adjustments thereto.

As shown in FIG. 18, the vertex portions of the trunnion segments 101and 102 are provided with centrally apertured bushing blocks 130' and131 through which the threaded member 125 extends, said blocks servingas guides for said threaded member. An apertured resilient deformableplate 132 may be provided between the apex portions of said trunnionsegments, as shown in FIG. 18,

serving as a yieldable cushioning filler between the trunnion segments.The threaded member 125 extends through the central aperture of saidcushioning filler 132, as is clearly shown in FIG. 18.

As will be readily apparent, the assembly 100 of FIGS. 15 to 18 can beemployed for substantially the same purposes as the clamps illustratedand described previously but may be employed with somewhat moreflexibility and ease of installation. The assembly 100 can be maneuveredso as to compensate for variations in distance between the riser and theleg to which it is to be attached. The clamp assembly 100 can beinstalled at the maximum stand-off distance, whereby the ends of theassembly will be at the same level. When there is a lesser distancebetween the leg and the riser, the two ends of the clamp may beinstalled at different levels, the trunnion segments 101 and 102 beingthen angled relative to the two sets of opposing jaw members. It willalso be apparent that in the event that the riser and the leg to whichit is to be attached are not parallel to each other, the clamp assembly100 can be installed and is adjustable for such non-parallelism.

As previously mentioned, the handwheel 129 may be manually operated bythe diver, or alternatively, may be driven by an external power sourceby utilizing a cable attached to the loops 130. As above mentioned, whenthe tightening procedure is completed, the diver can remove the cable bydisconnecting it from the loops 130.

The trunnion pins may be secured to the ends of the arms of the trunnionsegments in any suitable manner, for example, may be rigidly securedbetween the arm bars employing vertical retaining plates 140, 140 weldedbetween the bars on opposite sides of the pins. Furthermore, the pinsare provided with retaining collars 141 which cooperate with the headsof the pins to retain them against axial movement.

While certain specific embodiments of improved clamp assemblies forconnecting a riser to an adjacent stationary element of a platform orsimilar structure have been disclosed in the foregoing description, itwill be understood that various modifications within the spirit of theinvention may occur to those skilled in the art. Therefore, it isintended that no limitations be placed on the invention except asdefined by the scope of the appended claims.

What is claimed is:

1. A clamp assembly comprising a plurality of body members havingsubstantially semi-circular jaw portions, means pivotally connectingsaid body members together with said jaw portions in opposingrelationship to define two sets of pairs of opposing jaw portionsadapted to respectively engage around a fixed support member and anadjacent pipe, and means to secure said pairs of opposing jaw portionsin cooperating clamping relationship, wherein said securing meansincludes at least one threaded member arranged to exert clamping forceon at least one of the jaw portions and nut means threadedly engagedwith said threaded member and arranged to exert clamping force on a jawportion opposite said one jaw portion, and wherein said securing meanscomprises a coplanar pair of trunnion segments, each having a pair oftrunnion arms and a connection therebetween, the threaded memberextending through the junctions of the trunnion arms and beingsubstantially in the planes of the trunnion segments, said semi-circularjaw portions being respectively pivoted to the ends of the trunnionarms.

2. The clamp assembly of claim 1, and wherein the threaded memberpivotally connects the body members together on a pivotal axis locatedbetween the two sets of pairs of opposing jaw portions.

3. The clamp assembly of claim 2, and wherein said threaded member hasan axis substantially parallel to the planes of the respective pairs ofopposing jaw portions.

4. The clamp assembly of claim 1, and wherein said body members eachcomprises a plurality of parallel flat curved bar elements, and means tomaintain the plurality of bar elements of each body member in spacedparallel relationship.

5. The clamp assembly of claim 1, and wherein said threaded member isprovided with a hand wheel at one end thereof, said threaded memberhaving shoulder means adjacent the hand wheel abutting the adjacenttrunnion junction, the opposite trunnion junction being provided withnon-rotatable nut means threadedly receiving said threaded member.

6. The clamp assembly of claim 1, and wherein said body members eachcomprises a pair of parallel flat curved bar elements, and means tomaintain the bar elements in spaced parallel relationship.

7. The clamp assembly of claim 6, and wherein the threaded memberextends between the respective flat curved bar elements of each pair andis substantially parallel to the planes thereof.

References Cited UNITED STATES PATENTS 587,912 8/1897 Atwood 248--2301,280,095 9/ 1918 Smith 248230 1,852,363 4/1932 Parent 24868 X 1,883,93510/1932 Kelley 24874 X 3,207,463 9/1965 Downey 24868 X FOREIGN PATENTS23,395 5/1930 Australia 248230 CHANCELLOR E. HARRIS, Primary ExaminerUS. Cl. X.R.

2481 CC; 248221, 226 C

